Orthodontic treatments involve repositioning misaligned teeth and improving bite configurations for improved cosmetic appearance and dental function. Repositioning is typically accomplished by a dentist or orthodontist (hereinafter practitioner) applying gentle forces by a dental appliance (e.g., braces or positioning appliances) to a patient's teeth over an extended period of time. Due to the limited space within the oral cavity and extensive movements that some teeth must undergo, the teeth will often be moved throughout a series of intermediate patterns to properly arrange the teeth.
Braces comprise a variety of appliances such as brackets, bands, archwires, ligatures, and O-rings. After the brackets are bonded to the teeth, periodic meetings with the treating practitioner are required to allow them to reactively adjust the braces. This generally involves installing different archwires having different force-inducing properties, and/or replacing or tightening existing ligatures.
In contrast, positioning appliances or aligners are comprised of a thin shell of material that generally conforms to a patient's teeth but each appliance provides a teeth receiving cavity geometry that is slightly out of alignment with the initial tooth configuration. Placement of the aligner over the teeth applies controlled forces in specific locations to gradually move the teeth into a new configuration of a predetermined treatment plan. Repetition of this process with successive aligners, each providing a new unique teeth receiving cavity, eventually moves the teeth through a series of intermediate arrangements to a final desired arrangement in accordance with the predetermined treatment plan.
The force that will be generated by braces or an aligner system to teeth can be calculated by finite element analysis modeling. Currently, the systems that exist for obtaining such measurements suffer from issues of inaccuracy and their ability to look at multiple teeth and their movements relative to each other. Thus, it takes much time and effort to obtain a force measurement for multiple teeth within the jaw structure, and any result can rarely be replicated.